Combination ceiling tile and air duct structure

ABSTRACT

A heating and air conditioning duct system for installation in drop ceilings utilizing T-bar construction wherein ducts are formed of a suitable insulating light weight material and secured to ceiling tiles to provide the completed duct which can then be placed in position on the T-bars as in the case of conventional ceiling tiles. Bends and reducing sections may also be prefabricated so that the entire air distribution system can be installed in the course of installation of the ceiling and without the need for special sheet metal work which involves considerable time and expense.

United States Patent 1 Liberman Sept. 17, 1974 1 COMBINATION CEILING TILE AND AIR DUCT STRUCTURE [76] Inventor: Milton Liberman, 65 Seawane Rd,

East Rockaway, NY. 11697 [22] Filed: May 22, 1972 21 Appl. No.: 255,652

[52] US. Cl 52/220, 52/221, 52/484, 98/40, 138/149 [51] Int. Cl E04f 17/08, F24f 13/06 [58] Field of Search 52/220, 221, 484; 138/149; 98/40 D [56] References Cited UNITED STATES PATENTS 2,330,763 9/1943 Townsend .1 138/158 2,870,623 1/1959 Murray 52/220 X 2,937,589 5/1960 Rachlin 52/221 X 2,978,779 4/1961 Tatsch 52/169 X 3,687,170 8/1972 Malone 138/149 X 3,690,243 9/1972 Lambert 52/484 X Primary ExaminerAlfred C. Perham 5 7 ABSTRACT A heating and air conditioning duct system for installation in drop ceilings utilizing T-bar construction wherein ducts are formed of a suitable insulating light weight material and secured to ceiling tiles to provide the completed duct which can then be placed in position on the T-bars as in the case of conventional ceiling tiles. Bends and reducing sections may also be prefabricated so that the entire air distribution system can be installed in the course of installation of the ceiling and without the need for special sheet metal work which involves considerable time and expense.

17 Claims, 14 Drawing Figures T F- am 6/ PAIENIEB 3.835.606

SHEEI 2 0F I Pmmmssr l mu sum 30F 4 COMBINATION CEILING TILE AND AIR DUCT STRUCTURE This invention relates to drop ceiling structures and more specifically to a novel and improved combination tile and air duct structure for use in drop ceilings to facilitate the installation for heating and air conditioning without the need for extensive sheet metal operations prior to installation of the drop ceiling.

Drop ceilings are widely utilized in building construction to provide space for the accommodation of electric wiring, heating and air conditioning ducts, communication circuits, recessed lighting fixtures and the like. With reference to heating and air conditioning ducts, known procedures have entailed the installation of conventional sheet metal ducts prior to installation of the drop ceiling. In such cases it is necessary to determine the precise location of the air conditioning and heating outlets and, should it be desirable to change the position of a hot or cold air outlet after the ceiling is in position, a substantial amount of work is entailed as it may be necessary to actually remove portions of the drop ceiling to permit installation of additional sheet metal ducts. This invention overcomes the difficulties heretofore encountered in providing heating and air conditioning ducts and provides a novel and improved structure wherein the air duct and ceiling tile are combined so that the ducts are in effect supported by the drop ceiling. This procedure greatly reduces the cost of duct installation since pre-formed duct and tile structures can be installed simply and quickly in the installation of the drop ceiling. Furthermore, should any changes in the duct work be required, the ducts can be simply and easily removed and relocated in the ceiling to provide outlets in new desired locations.

Another object of the invention resides in the provision of a novel and improved combination air duct and ceiling tile wherein the pre-formed duct may be constructed either integrally with the tile or secured to the tile at the site of the installation.

Still another object of the invention resides in the provision of a novel and improved air duct and tile assembly which may be readily fabricated of a lightweight insulating material which avoids the need for insulation as required on metal ducts and which greatly simplifies installation and maintenance.

A still further object of the invention resides in the provision of a novel and improved air duct and tile combination for use in connection with drop ceilings having T-bar supporting members and wherein the duct and tile combinations are removably secured to the T- bars.

The duct and tile assembly in accordance with the invention consists of a pre-formed duct having dimensions coordinated with conventional tile sizes as utilized with drop ceiling structures so that the duct and tile can be readily assembled and secured one to the other and also to the T-bars in the ceiling when the duct and tile assembly is positioned therein. The invention further contemplates the provision of duct sections for reducing the duct area as well as curved sections so that air outlets can be positioned in any location in the room. If desired, air outlets may be readily provided by simply forming openings in the ceiling tile at any location and which openings merely communicate with the overlying duct.

The above and other objects of the invention will become more apparent from the following description and accompanying drawings forming part of this application.

In the Drawings:

FIG. 1 is a perspective view of a fragmentary portion of a drop ceiling showing the installation of an air duct assembly in accordance with the invention,

FIG. 2 is a perspective view of an air duct and tile assembly,

FIG. 3 is an exploded perspective view illustrating one mode of attachment of a preformed duct to a ceiling tile,

FIG. 4 is a cross-sectional view of FIG. 1 taken along the line 4-4 thereof,

FIG. 5 is a plan view of a drop ceiling structure showing a reducing section for reducing the duct area together with curved and straight duct sections of reduced area,

FIG. 6 is a cross-sectional view of FIG. 5 taken along the line 6-6 thereof,

FIG. 7 is a cross-sectional view of FIG. 5 taken along the line 77 thereof,

FIG. 8 is a plan view of a modified embodiment of a duct structure in accordance with the invention,

FIG. 9 is a perspective view of the means for attaching the duct to the ceiling tile,

FIG. 10 is a cross-sectional view of the assembly of the duct of FIG. 8 with a ceiling tile,

FIG. 11 is a cross-sectional view of FIG. 10 taken along the line 11-11 thereof,

FIG. 12 is a perspective view of a modified embodiment of an air duct for installation in drop ceilings,

FIG. 13 is a cross-sectional view of FIG. 12 taken along the line l313 thereof, and

FIG. 14 is a perspective view of one embodiment of a clip for use in the embodiment of the invention shown in FIGS. 12 and 13.

One embodiment of a combined ceiling tile and air duct structure in accordance with the invention is illustrated in FIG. 1. The drop ceiling is of conventional construction having a plurality of longitudinal T-bars 10 at conventional 1 foot or 2 foot spacings as the case may be, and transverse T-bar sections 11 spaced generally at 4 foot intervals and interlocked with the longitudinal T-bars 10 in the conventional manner. Ceiling tiles 12, or in the alternative a recessed lighting fixture, are positioned in the rectangular openings formed by the T-bars 10 and 11. While the T-bar runners 12 are of conventional size with the center leg extending substantially above the tile 12, the T-bars 11 preferably have center legs of reduced height so that they do not extend materially above the tile 12. The T-bar grid is generally supported by rods or wires 13 which are connected to the T-bars and anchored in the ceiling of the building.

The air duct sections 14 in accordance with the invention are carried between adjoining longitudinal T- bars 10 and each duct section 14 as shown in FIG. 1 preferably has a width corresponding to the space between T-bars l0 and a length corresponding to the distance between the transverse T-bars 11. Successive duct sections 14 are arranged to abut one another and the gap between successive sections may be readily closed by a suitable sealing means 15 such as metal straps cemented to the ducts, adhesive strips or the like. The duct sections 14 and the associated tiles l2 may be held in position between the T-bars by any suitable means as, for instance, tabs 16 which extend through cooperating openings in the vertical portions of the T-bars 10.

FIGS. 2, 3 and 4 illustrate one mode of attachment of a rectangular ceiling tile 12. The duct 14 in the illustrated embodiment of the invention is generally rectangular and has a top wall 17 and side walls 18 and 19. While the duct is essentially rectangular, it is of course evident that the duct may be made in other configurations such as semi-circular, trapezoidal and the like. The lower edge of each side wall 18 and 19 is provided with a metal channel denoted by the numeral 20 which has a bottom portion 21 and upwardly extending side walls 22 and 23. The upper edge of the side wall 23 has an inwardly formed flange 24 provided with a sawtoothed edge 25. The bottom wall 21 has a plurality of triangular tabs 26 which may be cut from the metal forming the bottom wall and bend downwardly as illustrated more clearly in FIGS. 3 and 4. The side wall 23 also has at least two outwardly extending tabs 16 which may be formed from the side wall material as illustrated and which engage cooperating openings in the T-bars as described in connection with FIG. 1. A channel is fastened to the lower edge of each side wall 18 and 19 of the duct 14 by inserting the side wall between the two upwardly extending walls 22 and 23 of the channel 20 and then compressing the channel 20 to urge the saw-toothed edge 25 into the side wall of the duct as shown in FIG. 4 to securely attach the channel to the duct. The duct 14 with the channels 20 secured to the lower edges of the side walls thereof may then be placed on a tile section 12 and the triangular tabs 26 forced into the tile. To seal duct 14 to the tile, the underside of the channels 20 may be cemented to the tile or a suitable strip of adhesive tape 27 may be adhered to the channel 20 and an adjoining surface of the tile 12. In this way an air tight seal is provided between the duct 14 and the tile 12.

The duct 14 may be made of any suitable material such as plastic or the combination of plastic and metal and formed by a suitable molding or other forming process and, if desired, lined with a thin layer of aluminum or other suitable metal. Similarly, the top surfaces of the tiles 12 which are to form part of the air duct may also be covered with a thin metallic sheet of aluminum or other suitable metal or, in the alternative, both the insides of the duct 14 and the top side of the tile 20 may be sprayed with a metallic paint. Room outlets can be readily formed by cutting openings in the tiles 12 such as the opening 28 as shown for instance in FIG. 2. If de sired, a suitable louver may be inserted in the opening. Particularly desirable materials for use in forming the ducts 14 are compressed polyurethane foam in the form of sheets and glass fiber sheets of the desired density having layers of aluminum foil 14 and 14" on each side thereof. The sheets are light in weight, can have any desired rigidity. and can be cut easily to desired sizes. With compressed sheets of polyurethane foam fiber glass or other similar plastic material wherein the outer surfaces are covered by aluminum foil, the sheets can be formed readily into shaped ducts, such as ducts 14 at the installation site. The compressed polyurethane foam or fiber glass sheathed in aluminum can be bent to form relatively sharp corners by placing the material on a surface with a portion extending beyond the surface edge. Then by applying downward pressure on the overhanging portion the material will fracture uniformly and precisely along the length of the bend without fracturing or breaking the aluminum sheaths. Moreover, bends substantially in excess of can be made without damaging the material or even weakening those portions adjacent to the bend. Accordingly, each duct length can be cut to size at the factory and the breaks formed in the proper locations. The material can then be shipped in flat form and be shaped and installed quickly at the site. One form of compressed polyurethane foam sheathed with aluminum foil is manufactured by the celotex Corporation and marketed under the name Technifoam and has a thickness of 9/16 inch.

In many instances it is necessary to reduce the area of the duct in order to provide adequate distribution of air. For this purpose a pre-formed reducing section such as the section generally denoted by the numeral 29 may be provided as shown in FIGS. 5 and 6. The reducing section may be formed in any desired manner and of any desired material such as metal, plastic, and combinations thereof. It is preferable however to use a suitable fireproof insulating material such as those described with at least the inner surface being sheathed with aluminum foil or other metal. The reduction in area is effected in a conventional manner, namely, by providing a duct section 30 which corresponds in area to a duct section 14 as previously described, a tapered section 31, and a straight section 32 of the desired reduced area. The reducing section 29 may be secured to a ceiling tile 12 in any suitable manner as, for instance, by cementing the duct section to the tile or by providing straps 33 which are shaped to engage a duct section and extend outwardly to engage cooperating openings in the adjoining T-bars 10. Pre-formed curved ducts such as the duct 34 and cooperating straight sections 35 may also be provided and secured in position on the tiles 12 by transverse straps 33. While the transverse straps may be formed in any desired manner and of either plastic or metal, it may be desirable to provide reinforced straps such as the strap shown for instance in FIG. 7 and denoted generally by the numeral 36. The strap 36 includes a flat strip 37 which is formed to fit the duct section 35 as shown in FIG. 7 and having end portions lying flat against the tile portion 12. Webs 38 are secured to at least one side edge of the strap 37 and, thus, afford substantial rigidity to the strap 37 causing it to tightly engage the duct 35. If desired, the duct sections 35 as shown in FIG. 7 as well as the duct sections 34 and 29 may be sealed to the ceiling tile by cement or strips of adhesive tape 39 as shown in FIG. 7.

A modified embodiment of the invention is shown in FIGS. 8 through 1 1. A duct section denoted by the numeral 40 and formed of compressed polyurethane foam of inch to We inch in thickness is cut to size and the preliminary breaks 4] and 42 are formed therein. Duct attaching means 43 and 44 each comprising a metal angle 45 with an adhesively coated strip 46 attached to and extending from one leg thereof is provided on each end of the duct section 40. The adhesive strip 46 is attached to the underside of the polyurethane board 40 as shown in FIG. 8 so that the edge of the board is spaced from the upwardly extending leg 45 of the angle 45, a distance equal to the thickness of the ceiling tile 47.

Each strip 43 has a pair of end lugs 48 of a light gauge material and a plurality of intermediate lugs 49. In the instant embodiment of the invention, the lugs are welded to the leg 45" of the angle 45 and the lugs 49 have a V-shaped portion with the ends thereof extending through an opening 50. When the duct 14 is formed from the sheet 40 as shown in FIG. 10, the lower edges 51 of the duct are cemented to the ceiling tile 47 and then the angles 43 and 44 are moved into engagement with the tile 47 and with the legs 45 underlying the tile. The lugs 48 and 49 are then forced into the tile 47 to provide the completed assembly for installation in the ceiling.

In the foregoing structure, adhesive tape is used to effect the joinder of the tile 47 with the duct 14. It is evident that metal clips may be used to engage both the ceiling tile 47 as well as the walls of the duct 14 since the duct material can be pierced readily. The ceiling tile 47 also preferably has an inner aluminum layer 46' and an outer decorative layer 47".

FIGS. 12 through 14 illustrate a modified embodiment of the invention which is particularly useful with drop ceilings wherein the space between the supporting surface and the drop ceiling is too shallow to accommodate a duct of the desired cross-sectional area. In this case the duct in accordance with the invention depends from the plane of the ceiling and is arranged so that its outer surface has the same finish as the exposed surfaces of the ceiling tile.

More specifically, the drop ceiling generally denoted by the numeral 60 includes longitudinal and transverse T-bars 61 and 62 as in a conventional drop ceiling. The T-bars form essentially rectangular openings which are closed by ceiling tile 63, lighting fixtures as previously described or by air duct sections 64 as illustrated. Each air duct section 64 includes a depending channel having a bottom wall 65 and upwardly extending side walls 66, the latter terminating in outwardly extending flanges 67. The top side of the channel is closed by a sheet 64 cemented or otherwise secured to the flange portions 67. For instance, U-shaped strips 68 may be utilized to engage the sheet 64' with the flanges 67. Each strip 68 includes a top wall 69, a side wall 70, and a bottom wall 71. The bottom wall 71 includes an upwardly extending toothed flange 72 to firmly engage the underside of the associated flange 67.

The channels 64 and sheets 64' are preferably made of an insulating material and in the same manner as described in connection with the embodiment of the invention shown in FIGS. 1 and 2. In this case, however, the lower surface of each sheet 64' and the inner surface of each channel 64 should be coated with a metal foil, sprayed or otherwise treated to render it substantially impervious to moisture and dust and dirt particles. The exposed surfaces of channels 64 should be provided with the same decorative surfaces as the exposed surfaces of the tiles 63. If desired, means such as tabs 73 may be used to firmly engage the channels 64 with the T-bars.

With the invention as described above, ducts for heating and air conditioning can be readily and easily installed in the course of installation of the drop ceiling with the result that both the time and cost for duct installation can be drastically reduced. By forming the duct sections of an insulating material, additional insulation is not required, and of course noise is materially reduced. The invention'also facilitates modification of duct systems required as the duct sections can be readily removed and replaced to provide outlets in any desired location in a room.

While only certain embodiments of the invention have been illustrated and described, it is understood that alterations, changes and modifications may be made without departing from the true scope and spiritthereof as defined by the appended claims.

What is claimed is:

1. An air duct for drop ceilings having longitudinal and transverse members for supporting ceiling tiles, a U-shaped channel having outwardly extending legs, a sheet bridging said legs, said channel and sheet being supported by said longitudinal and transverse members.

2. An air duct for drop ceilings according to claim 1 wherein successive sheet and channel combinations are joined in end-to-end relationship and means are provided for sealing the abutting edges of said combinations.

3. An air duct for drop ceilings according to claim 1 wherein said channel is formed of a relatively dense plastic insulating material having an aluminum sheet bonded to at least the inner side thereof.

4. An air duct for drop ceilings according to claim 1 wherein said channel extends upwardly from said sheet and said sheet is in the form of a ceiling tile provided with openings extending therethrough for the discharge of air from said duct.

5. An air duct for drop ceilings having longitudinal and transverse members for supporting ceiling tiles, a U-shaped channel having outwardly extending legs, a sheet bridging said legs, said channel and sheet being supported by said longitudinal and transverse members, the legs of said channel being cemented to said sheet and said sheet is in the form of a ceiling tile mechanically secured to said channel by fastening means.

6. An air duct for drop ceilings according to claim 5 wherein said fastening means comprise clips secured to said channel legs and said ceiling tile.

7. An air duct for drop ceilings according to claim 2 wherein the sealing means for said abutting edges include strips bridging adjoining channels and fixedly secured thereto.

8. An air duct for drop ceilings according to claim 5 wherein said longitudinal and transverse members are inverted T-bars and said fastening means include tabs engaging at least certain of said T-bars.

9. An air duct for drop ceilings according to claim 1 wherein said channel has a cross-sectional area in the plane of the ends of said legs smaller than the area of said sheet and said legs are provided with outwardly extending means defining an area substantially equal to the area of said tile.

10. An air duct for drop ceilings according to claim 'tion of the longitudinal T-bars having a height greater than the thickness of the tile and the transver T-bars having a height approximately equal to the thickness of the tile.

12. An air duct for drop ceilings according to claim 1 wherein said channel is formed of glass fibers compressed into a sheet and sheathed with metal foil.

13. An air duct for drop ceilings according to claim 12 wherein said longitudinal and transverse members are inverted T-bars with the upwardly extending portion of the longitudinal T-bars having a height greater than the thickness of the tile and the transverse T-bars having a height approximately equal to the thickness of the tile.

14. An air duct according to claim 1 wherein said channel is of non-uniform cross-sectional area.

15. An air duct according to claim 1 wherein said channel is curved in the plane of the ends of said legs.

pending therefrom. 

1. An air duct for drop ceilings having longitudinal and transverse members for supporting ceiling tiles, a U-shaped channel having outwardly extending legs, a sheet bridging said legs, said channel and sheet being supported by said longitudinal and transverse members.
 2. An air duct for drop ceilings according to claim 1 wherein successive sheet and channel combinations are joined in end-to-end relationship and means are provided for sealing the abutting edges of said combinations.
 3. An air duct for drop ceilings according to claim 1 wherein said channel is formed of a relatively dense plastic insulating material having an aluminum sheet bonded to at least the inner side thereof.
 4. An air duct for drop ceilings according to claim 1 wherein said channel extends upwardly from said sheet and said sheet is in the form of a ceiling tile provided with openings extending therethrough for the discharge of air from said duct.
 5. An air duct for drop ceilings having longitudinal and transverse members for supporting ceiling tiles, a U-shaped channel having outwardly extending legs, a sheet bridging said legs, said channel and sheet being supported by Said longitudinal and transverse members, the legs of said channel being cemented to said sheet and said sheet is in the form of a ceiling tile mechanically secured to said channel by fastening means.
 6. An air duct for drop ceilings according to claim 5 wherein said fastening means comprise clips secured to said channel legs and said ceiling tile.
 7. An air duct for drop ceilings according to claim 2 wherein the sealing means for said abutting edges include strips bridging adjoining channels and fixedly secured thereto.
 8. An air duct for drop ceilings according to claim 5 wherein said longitudinal and transverse members are inverted T-bars and said fastening means include tabs engaging at least certain of said T-bars.
 9. An air duct for drop ceilings according to claim 1 wherein said channel has a cross-sectional area in the plane of the ends of said legs smaller than the area of said sheet and said legs are provided with outwardly extending means defining an area substantially equal to the area of said tile.
 10. An air duct for drop ceilings according to claim 1 wherein said channel is formed of a single sheet of compressed polyurethane foam sheathed on at least one side with a continuous sheet of aluminum foil.
 11. An air duct for drop ceilings according to claim 10 wherein said longitudinal and transverse members are inverted T-bars with the upwardly extending portion of the longitudinal T-bars having a height greater than the thickness of the tile and the transver T-bars having a height approximately equal to the thickness of the tile.
 12. An air duct for drop ceilings according to claim 1 wherein said channel is formed of glass fibers compressed into a sheet and sheathed with metal foil.
 13. An air duct for drop ceilings according to claim 12 wherein said longitudinal and transverse members are inverted T-bars with the upwardly extending portion of the longitudinal T-bars having a height greater than the thickness of the tile and the transverse T-bars having a height approximately equal to the thickness of the tile.
 14. An air duct according to claim 1 wherein said channel is of non-uniform cross-sectional area.
 15. An air duct according to claim 1 wherein said channel is curved in the plane of the ends of said legs.
 16. An air duct for drop ceilings according to claim 1 wherein said channel depends from said longitudinal and transverse members.
 17. An air duct for drop ceilings according to claim 1 wherein the legs of said channels include outwardly extending flanges, said sheet is secured to the outer surfaces of said flanges and said flanges engage said longitudinal and transverse members with said channel depending therefrom. 